Originally Posted by TK-421
The S63 does have an aluminum block but also has cast iron sleeves to help the motor handle high boost, unlike the S65 (aluminum sleeves).
And yes, I do know FI strokers (pencilgeek, for example) exist - supercharger strokers.
Who said S65 is sleeved? i don't know about S63 but S65 isn't sleeved. The only sleeved running S65's are stage 3 Gintanis.